electron/browser/api/atom_api_event_emitter.h
2013-06-18 18:35:08 +08:00

71 lines
2.2 KiB
C++

// Copyright (c) 2013 GitHub, Inc. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef ATOM_BROWSER_API_ATOM_API_EVENT_EMITTER_H_
#define ATOM_BROWSER_API_ATOM_API_EVENT_EMITTER_H_
#include <iosfwd>
#include "base/basictypes.h"
#include "vendor/node/src/node_object_wrap.h"
namespace base {
class ListValue;
}
namespace atom {
namespace api {
// Class interiting EventEmitter should assume it's a javascript object which
// interits require('events').EventEmitter, this class provides many helper
// methods to do event processing in C++.
class EventEmitter : public node::ObjectWrap {
public:
virtual ~EventEmitter();
// Emit an event and returns whether the handler has called preventDefault().
bool Emit(const std::string& name);
bool Emit(const std::string& name, base::ListValue* args);
// Same with Unwrap but if the handle is not a native object, which happened
// when user inherits a native class, we would search for the native object,
// otherwise we won't get the correct C++ object.
template <typename T>
static inline bool SafeUnwrap(v8::Handle<v8::Object> handle, T** pointer) {
v8::Handle<v8::Object> real_handle = SearchNativeObject(handle);
if (real_handle->InternalFieldCount() == 0)
return false;
*pointer = Unwrap<T>(real_handle);
return true;
}
// Helper function to call "new" when constructor is called as normal
// function, this usually happens when inheriting native class.
//
// This function also does some special hacks to make sure the inheritance
// would work, because normal inheritance would not inherit internal fields.
static v8::Handle<v8::Value> FromConstructorTemplate(
v8::Persistent<v8::FunctionTemplate> t,
const v8::Arguments& args);
// Small accessor to return handle_, this follows Google C++ Style.
v8::Persistent<v8::Object> handle() const { return handle_; }
protected:
explicit EventEmitter(v8::Handle<v8::Object> wrapper);
static v8::Handle<v8::Object> SearchNativeObject(
v8::Handle<v8::Object> handle);
private:
DISALLOW_COPY_AND_ASSIGN(EventEmitter);
};
} // namespace api
} // namespace atom
#endif // ATOM_BROWSER_API_ATOM_API_EVENT_EMITTER_H_